Method of conveying and treating metallic sheets



March 17, 1942. F. EBERHART 2,276,471

METHOD OF CONVEYING AND TREATING METALLIC SHEETS- Filed Oct. .20, 1939 'III'JIIIIIIIIl/III IIIIIIIIIIIIIIIIIIIIII'IIll 1",,"

Patented Mar. 17, 1942 UNITED STATE.

PATENT OFFICE METHOD OF CONVEYING AND TREATING METALLIC SHEETS Felix Eberhart, Arlington, N. J., assignor to American Can Company, New York, N. Y., a corporation of New Jersey Application October 20, 1939, Serial No. 300,477

2 Claims.

The present invention relates to a method of conveying metallic sheets and the like and has particular reference to magnetically retaining f the sheets in a predetermined flat position while conveying them along a predetermined path of travel for treatment of the sheets.

An object of the invention is the provision of a method of conveying flexible metallic sheets orthe like wherein the sheets are moved along a predetermined path of travel through a magnetic field which holds them in a flat condition on a non-magnetic surface so that the sheets may be readily operated upon in such flat condition.

Another object is the provision of such a method of conveying flexible metallic sheets wherein the sheets are carried in a flat position on a non-magnetic conveyor and while so moving the sheetspass through a magnetic field whereby the sheets are drawn into close contact with the conveyor to permit satisfactory operation on the sheets while moving with the conveyor.

Another object is the provision of a method of this character 'of conveying flexible sheets wherein an intimate contact between the conveyor and the sheets is maintained so that more ideal heat transfer conditions may be effected between the conveyor and the sheets.

Another object isthe provision of such a method of conveying sheets wherein the sheets are carried on a non-magnetic belt which is wider than the sheets, the belt passing through a'magnetic field which draws the sheets tightly against one side of the belt, and wherein a liquid cooling medium is projected against the opposite side of the belt so that the sheets will be quickly cooled by intimate contact with the belt and yet will be shielded from direct engagement with the cooling 4 medium.

Numerous other objects and advantages of the.

invention will be apparent as it is better understood from the following description, which, taken in connection with the accompanying drawing, discloses a preferred embodiment thereof.-

Referring to the drawing:

' Figure 1 is a top plan view of an apparatus for carrying out the steps of the instant method invention, with parts broken away;

Fig. 2 is a longitudinal section of the apparatus illustrated in Fig. 1;

Fig. 3 is an enlarged longitudinal section showing a detail of the apparatus, the view being taken substantially along the line 3-4 in Fig. 1;

and

Fig. 4 is an enlarged transverse sectional detail taken substantially along the line 4-4 in Fig. 1. As a preferred embodiment of the instant invention the drawing illustrates an apparatus for carrying out the method wherein sheets A, for

example freshlylithographed and dried tinplate, are received in a heated condition as from 'a drying oven, indicated by the letter B, and are passed through 'a cooling mechanism C in which the temperature of the sheets is quicklyreduced to a minimum so that further handling of the sheets or operations thereon, for example in the manufacture of tubular sheet metal can bodies,

7 may be eifected without undue delay. It will be understood however that the instant improved procedure isequally adapted to be carried out by means of apparatus'other than that illustrated.

In the form of apparatus illustrated in the drawing, the hot dried lithographed sheets A are conveyed from the oven Bin a fiat or horizontal.

plane by way of .a continuously moving endless belt H (Figs. 1 and 2). This belt takes over a pulley I2 mounted on a cross shaft l3. j'ournaled in bearings it formed in brackets l5 secured to 'side frame l6 which constitutes the main frame of the cooling mechanism C. The belt I I may be driven in any suitable manner in time with the moving parts of the cooling mechanism.

At the discharge end of the oven belt H the hot sheets A are delivered into the cooling mechanism C and are received on an endlessbelt cooling conveyor H which preferably extends the full length of the cooling mechanism. The conveyor carries the sheets along a predetermined path of travel, which process constitutes a step in the instant method.

This conveyor is made of non-magnetic material, preferably stainless steel suitably treated or alloyed to render'the same non-magnetic, and

is of suflicient width to accommodate the sheets in end-to-end arrangement'without any portion of them extending beyond the edges of the conveyor. The top run of the conveyor 2| is in the same plane as the top run of the oven belt Ii and is arranged in end-to-end relation to the oven belt so that the sheets may be readily delivered onto the conveyor. v

The non magnetic conveyor 2! takes over a pair of large pulleys 23 which are located one at each end of the cooling mechanism C and are disposed between the side frames l8. These pulleys are respectively mounted on cross-shafts 24,-

one disposed at each end ot the conveyor 2|. At the entrance end of the conveyor one of these pulleyshaftsis Journaled in bearings 25 (Fig. 1)

formed in the brackets l5. At the opposite or discharge end of the mechanism the pulley shaft 24 is mounted in bearings 21 (Fig. 1) formed in brackets 28 which are secured to the side frames l6. This latter mentioned shaft 24 at the discharge end of the conveyor, is preferably the driving shaft and for this purpose is provided with a gear 29 (Fig. l) which may be rotated from any suitable source of power, such as an electric motor or other prime mover.

The conveyor 2! is maintained in a taut con dition by a belt tightener pulley 3| disposed in a pair of spring held side arms 32 mounted on a cross shaft 33 carried in bearing brackets 34 secured to the side frames Hi. This belttightener engages against the lower run of the conveyor and thus pulls the upper run straight and taut.

In order to prevent sagging of the upper run of the conveyor 2| the latter is supported on a plurality of spaced rollers 4! which are disposed 'transversely of the cooling mechanism These rollers are mounted on short cross shafts 42 carried in notches- 43 formed in the sides of a pluraiity of channel beams 44 which extend the full length of the mechanism between the conveyor pulleys 23. The rollers are preferably mounted in pairs on each shaft 42. One roller of each pair is disposed in the channel and the other roller extends across the open space between adjacent channels.

There are preferably three of these channel beams shown in the drawing and they are supported-on the top edges of an open top drain tank 46 which is located under theupper run of the conveyor. The drain tank in turn is supported on cross-beams 41 which are secured to the side frames l6 of the cooling mechanism.

As a step in the instant invention the sheets on the conveyor are carried over a magnetic field which draws the sheets into close contact with the conveyor. This magnetic field is located adjacent the rollers ll and is created by a plurality of stationary permanent magnets which are disposed in the channel beams 44 and which are insulated from the beams by insulating spacer blocks 52. These magnets are preferably of an elongated rectangular shape of U-shaped cross section as best seen in Figures 1 and 4. They are placed in staggered positions throughout the entire area between the conveyor pulleys 23 and are just high enough so that their tops are ad'- jacent but not touching the stainless steel conv veyor continuously moving above them.

Hence when a sheet A to be cooled is delivered conveyor over its path of travel. The conveyor being of a non-magnetic nature has no attracting properties to make the sheet adhere to it but just as soon as the sheet reaches the region of the magnets 5| the latter draw it down tight and retain it in a predetermined position against the top surface of the conveyor so that the entire sheet is perfectly fiat against the conveyor. This magnetic force drawing the sheet is indicated by short arrows shown in Fig, 3. Thus an ideal condition for heat transfer by conduction betweenthe conveyor and the sheet obtains as the conveyor carries the sheet forward.

While the sheet is so held and as a furtherstep of the invention, a cooling medium is projected against the bottom of the upper run of the conveyor to initially keep the conveyor cool and through it to cool the sheets. -Such a method of cooling the sheets has a double advantage. First the intimate surface contact of the entire sheet with the conveyor surface tends to promote effectual and rapid heat exchange, thereby pro-- viding for efficient cooling of the sheet, and second, the wide conveyor acts as a shield to protect the sheets from coming into direct contact with the cooling medium.

In the illustrated preferred embodiment of the invention a liquid cooling medium, such as water,

is used and this cooling medium is projected from falls back into the drain tank 46 from which it is drained off as desired or returned to the main supply source for re-circulation. For this purpose there is provided a drain pipe (Fig. 2)

which is threaded into the tank wall near its bottom. I

At the discharge end of the conveyor 2| the cooled sheet is carried out of the region of' the permanent magnets and hence it is no longer held attracted to the conveyor but rather is again free and ready to be discharged. The discharge of the sheet is effected by an endless belt 61 which is disposed adjacent the end of the conveyor with its upper run in the same plane as the upper run of the conveyor. Hence a sheet on the conveyor readily travels forward onto the discharge belt 61 and is carried away to any suitable place of deposit.

This discharge belt 61 takes over a pulley 68 mounted on a cross shaft 69- carried in bearings H formed in the conveyor brackets 28. The belt is actuated in any suitable manner in time with I the conveyor 2| so that the sheets may be carried away in regular order without interfering with the following sheets.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the steps of the process described and their order of accomplishment without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the process hereinbefore deonto the conveyor 2|, itis carried along with the 5:,

scribed being thereof.

I claim: 1. The method of cooling flexible metallic sheets having exposed heat treated surfaces, which consists in supporting the sheets while moving the same in processional order in a premerely a preferred embodiment determined path of travel through a magnetic This main field to a magnetic pull exerted in a direction normal to the plane of said sheet to draw and hold' the same firmly and intimately against one side of the supporting medium, and projecting spaced sprays of cooling medium against the op- 10 posite side of said supporting medium while the heated sheets are intimately and magnetically held the'reagainst by said magnetic pull and while shielding the sheets by said supporting medium from direct contactrwith the cooling medium,

whereby to eflect eflicient heat transfer by conduction from said heated sheets to said cooled supporting medium. I I FELIX EBERHART. 

